An improved method has been developed for determination of platelet low density lipoprotein receptor （LDL）. LDL was isolated by improved discontinuous density gradient ultracentrifugation. Iodogen method was used for radiolablling and platelet was separated by centrifugation-washing method. LDLR activity was assessed with receptor radioligand binding assay and Bmax. and KD were calculated based on mass action law. The results denoted that this improved method is simple

effective and practical.